Multilamp fixtures for illuminating



United States Patent MULTILAMP FIXTURES FOR ILLUMINATING SYSTEMS 0FCONSIDERABLE LENGTH Eberhard Leuze and Josef Mller, Neheim-Huesten,Germany Application October 2, 1950, Serial No. 187,872 Claims priority,application Germany October 3, 1949 Claims. (Cl. 24U-51.11)

This invention relates to lamp fixtures or luminaries for straightfiuorescent lamps intended for illuminating spaces of considerablelength.

One object of the invention is to provide a lamp fix ture of increasedruggedness and simplicity which may be readily assembled anddisassembled.

Another object of the invention is to provide a lamp fixture having avery high bending strength, yet a relatively small weight, requiring aminimum of points of suspension on account of its great bendingstrength.

Still another object of the invention is to provide a lamp fixturehaving common means for attaching the xture to a ceiling andfor securingauxiliary apparatus and wiring to the fixture.

A further object of the invention is to provide a lamp fixture having atop portion of such geometrical configuration as to impart a greatbending strength to the top portion, the top portion forming a dualpurpose rail, its dovetail-shaped outer surface constituting a supportfor fixture auxiliaries arranged inside of the fixture.

These and other objects of this invention will become more apparent uponconsideration of the following description of preferred embodimentsthereof, when taken in connection with the attached drawing in which:

Fig. l is a transverse cross-sectional view of an ernbodiment of theinvention with certain parts shown in elevation;

Fig. 2 is a front view of a component of the structure of Fig. 1;

Fig. 3 is a side elevation, on a smaller scale, of a group of fixturesof considerable length;

Fig. 4 illustrates the points of suspension of fixtures on a ceiling;and

Fig. 5 is a top plan view of the structure shown in Fig. 3.

Reference numeral 1 has been applied to a housing which may be providedwith lateral reflectors 2. As shown in Fig. 3 the length of the housing1 is a plural of the length of a straight tubular lamp as, for instance,a conventional fiuorescent lamp 3. Reference numeral 4 indicates thelamp holders of which one pair is associated with each lamp. Each lampholder 4 is attached to the housing 1 by means of a lamp holder support5. Housing 1 is closed at the lower side thereof by a bottom plate 6attached to and supported by the lamp holder support 5. Fig. l shows aballast choke 7 arranged inside or" the housing 1. The latter isattached to the ceiling by a hanger rod 8. The lower end of rod 8 isscrewthreaded for supporting a substantially U-shaped sheet metalelement or strap. The ends of the flanges 9 and 1t) of that element arebent to form a dovetail-shaped clamp adapted to be tightened by means ofa transverse bolt 12 and a tightening nut riding on a screw-threaded endof' said bolt. The above dovetail-shaped clamp is adapted to slide on astraight rail 11 formed on the top of housing 1 and extendingsubstantially along its entire length. According to Fig. l the top orroof of the A 2,734,995 lcc Y Patented Feb.14,1956

housing 1 itself is dovetail-shaped and constitutes the rail 11.

As shown in Fig. l the upper outer side of rail 11 is engaged bysupporting clamp element 9, 10, 12, while the lower inner side of rail11 is engaged by another supporting clamp 13, 14 which is likewisesubstantially dovetail-shaped. The top of housing 1 and an extension ofclamping element 14 form jointly a short passage or duct supportingcurrent conductors or leads 15. The center portion of supporting clamp13, 14 carries a piece of auxiliary equipment such as a ballast choke 7.

The housing 1 shown in Fig. 1 is provided on the lower lateral sidesthereof with diverging edge strips 16. The concave refiector 2 issecured to the left hand edge strip.

As shown in Fig. l the lamp holder supports 5 are provided at theiropposite lateral ends with clamping means 21 in cooperative engagementwith the Z-shaped ends of edge strips 16. The lamp holder support 5carries also the bottom cover plate 6.

A plurality of hanger rods 8 each having dovetailshaped clamping means9, 10, 12 at the lower end are arranged along rail 11. The number ofhanger rods per unit of rail length and their spacing may be varied, asdesired. Due to the high degree of rigidity of the top portion of thefixture a relatively small number of points of suspension are requiredfor a given length as, for instance, two points of suspension for each 5yards length.

Figs. 3 and 5 show clearly how a luminaire of very considerable lengthis formed by alignment of a plurality of luminaire units and alignmentof a plurality of tubular lamps. The aligned luminaire units form acontinuous composite luminaire structure and the spacing between theadjacent ends of the tubular lamps is extremely small, thus creating theimpression that there is but one single lamp the length of which issubstantially equal to that of the composite luminaire. In Fig. 4reference numeral 20 has been applied to indicate the points ofsuspension of the hangers 8 on a ceiling, which points may be out ofalignment if suitable adjustment means are provided enabling alignmentof the lower ends of hangers 8 along the line of symmetry 21 of casing1.

As clearly shown in Fig. l the substantially channelshaped casing 1forms lateral edges Z5, 25 between the top portion and the sides 26, 26'thereof. The top consists of a plurality of angularly bent integralelements including two lateral pairs of elements 29, 30 and 29, 39 and amedian element 27 arranged between said two lateral pairs of elements.Each of said plurality of elements encloses an acute angle with theelement immediately adjacent thereto, i. e. elements 30 and 29 enclosean acute angle, elements 29 and 27 enclose an acute angle, elements 27and 29 enclose an acute angle and elements 29 and 30 enclose an acuteangle. The angles enclosed between side 26 and element 30 and the angleenclosed between side 26 and element 30 are less than degrees. Themedian element 27 lies substantially fiush with the plane defined byedges 2S and 25" and forms jointly with elements 29, 29 a straighthollow rail 11 having a dovetail-shaped cross-section. Rail 11 isrecessed within the general outline of casing 1 and is hugged externallyby the clamping, means 9, 10, 12 and internally by the wedge-shapedclamping means 13, 14. Reference numerals 31 and 31 have been applied toindicate the edges formed between elements 29 and 30, and 29 and 30',respectively. The above described geometry of casing 1 provides a highdegree of rigidity of the top of casing 1.

Having described preferred embodiments of the invention in accordancewith the patent statutes, it is desired that the invention be notlimited to these particular structures, inasmuch as it will be obviousto persons skilled in the art that many modications and changes may bemade in these particular structures .without departing from the broadspirit and scope of the invention. Accordingly, it is desired that theinvention be interpreted as broadly as possible and that it be limitedonly as required by the prior art.

We claim as our invention:

1. A lamp fixture comprising a substantially channelshaped casing havinga top and a pair of sides, said top and pair of sides forming a pair oflateral edges at the intersection of the planes thereof, said topconsisting of tive angularly bent integral elements each enclosing anacute angle with the element situated immediately adjacent thereto, twoof said five elements each enclosing an angle of less than 90 degreeswith one of said pair of sides, said tive elements comprising a medianelement and two lateral pairs of elements, said median element lyingsubstantially iiush with the plane deiined by said pair of lateral edgesand forming jointly with two of said tive elements situated adjacentthereto a straight hollow rail, said rail being substantially recessedin back of the plane defined by said pair of lateral edges and grippedby suspension clamps at the outer surface thereof, a wedge-shaped clampsupporting auxiliary fixture equipment engaging the inner surface ofsaid rail.

2. A lamp fixture comprising a substantially channelshaped casing havinga top and a pair of sides, said top and pair of sides forming a pair oflateral edges at the intersection of the planes thereof, said topconsisting of a plurality of angularly bent integral elements eachenclosing an acute angle with the element situated immediately adjacentthereto, two of said plurality of elements each enclosing an angle ofless than 90 degrees with one of said pair of sides, said plurality ofelements comprising a median element and two lateral pairs of elementssubstantially recessed behind the plane deiined by said pair of lateraledges, the angular relations of said plurality of elements and said pairof sides imparting a great freedom of lateral motion to said pair ofsides.

3. In a lamp lixture for straight iiuorescent lamps of considerablelength a trough of sheet material having a top and two sides convergingtoward said top, a hollow rail dove-tail shaped in cross-sectioncompletely recessed behind the plane defined by the top edges of saidsides forming an integral part of said top, said top and said sidesdefining a pair of grooves extending in a direction longitudinally ofsaid trough and situated behind said plane deiined by said top edges ofsaid sides, a first clamping means for suspending said trough projectinginto said pair of grooves and engaging the outer surface of said rail,and a second clamping means for supporting auxiliary equipment inengagement with the inner surface of said rail.

4. In a lamp iixture for straight fluorescent lamps of considerablelength a trough of sheet material having a top and two sides divergingfrom said top, a hollow rail dove-tail shaped in cross-sectioncompletely recessed behind the plane delined by the top edges of saidsides forming an integral part of said top, said top further comprisinga pair of surface elements each slantng from one of said top edges ofsaid sides to one of the bottom edges of said rail, a first clampingmeans for suspending said trough projecting at least in part beyond saidplane delined by said top edges of said sides and cooperatively engagingthe outer surface of said rail, a second clamping means for supportingauxiliary equipment, said sec ond clamping means comprising a pair ofclamping bars arranged transversely with respect to said trough, one ofsaid pair of clamping bars cooperatively engaging the inner surface ofsaid rail and the other of said pair of clamping bars cooperativelyengaging the inner surfaces of said pair of surface elements, and anextension on said other of said pair of clamping bars forming a supportfor Wiring arranged in said trough.

5. A trough of sheet material for lamp xtures for straight fluorescentlamps of considerable length comprising a top and a pair of sidesdiverging from said top, a hollow rail dove-tail shaped in cross-sectioncompletely recessed behind the plane defined by the top edges of saidsides forming an integral part of said top, and said top furthercomprising a pair of surface elements each slanting from one of said topedges of said sides to one of the bottom edges of said rail.

References Cited in the rile of this patent UNITED STATES PATENTS MonksFeb.v 23, 1954

